Summer solstice on Sunday June 21 marks longest day

The summer solstice arrives on Sunday, June 21, marking the longest day of the year and the official start of astronomical summer in the Northern Hemisphere. The precise moment will occur at 4:24 a.m. Eastern Daylight Time, when the sun reaches its highest point in the sky and the Northern Hemisphere is tilted most directly toward the sun.

This celestial event is caused by Earth’s 23.5-degree axial tilt. At the solstice, the sun appears directly overhead at the Tropic of Cancer, an imaginary line located approximately 23.5 degrees north of the equator. The result is the maximum period of daylight and the shortest night of the year. Conversely, in the Southern Hemisphere, June 21 marks the winter solstice, the shortest day and the beginning of winter.

The amount of daylight varies significantly by latitude. In far northern locations like Utqiaġvik, Alaska, the sun will be up for a full 24 hours, while Fairbanks will experience nearly 22 hours of daylight. Cities in the northern United States, such as Seattle and Minneapolis, will see roughly 15 to 16 hours of sun. Farther south, in cities like Atlanta and Miami, daylight will last between 13 and 14 hours.